Tips for Training in Hot Weather

Beers, burgers, and county-fair funnel cake aren’t the only things that might weigh you down this summer: sweltering weather can make even a short run feel like a trudge through six inches of mud. As the sun beats down, your core temperature shoots up, sending blood away from muscles to the surface of skin to help heat dissipate.

It’s uncomfortable, but science says training in the heat is worth the trouble: Hot-weather workouts teach your body to sweat more (which keeps you cool), increase your blood-plasma volume (which benefits cardiovascular fitness), and lower your core body temp—all adaptations that help you perform better in any weather. But how hot is too hot? “I tell people to use caution when it’s more than 80 degrees out, or 90 degrees if you’re heat-acclimatized, and if the humidity is high, you need to make even more adjustments,” says Douglas Casa, Ph.D., head of the University of Connecticut’s Korey Stringer Institute, which studies enhancing performance in the heat. Follow these specific tweaks depending on what you’re training for.

If you’ve penciled in a long run and starting at 4 or 5 a.m. isn’t an option, make sure you’ve had a solid night’s rest, which enhances heat tolerance, says Casa. Avoid out-and-back routes (which don’t give you the option to bail), and tweak your expectations: “Many of us are around 10 percent slower in the heat,” says Casa. Try running for time instead of distance on super-hot days: If an 18-miler normally takes you three hours (10:00 pace), run for three hours at the same effort level.

Cheryl Seligman

Prep for postwork races by packing hydrating fruit and veggie snacks (like carrots, cucumbers, strawberries, and cantaloupe) to nosh on throughout the day. And chill a bandanna to wrap around your neck during the run: A recent study found that such cooling tactics during a race are more effective than precooling strategies when it comes to boosting performance in the heat. You’ll also want to halve your standard warmup to avoid overheating, says Ben Rosario, head coach of Hoka One One Northern Arizona Elite. So if you typically jog for 10 minutes and do dynamic stretches for 10 minutes prerace, do each for five instead—your muscles warm up more quickly in hot conditions. Set goals depending on how the elements look that day. One idea is to focus on place instead of time: If you know you’re among the top 50 in a given race on a cooler day, shoot for the same approximate place when it’s hot.

Stay flexible as you cross off your two or three swimming, biking, and running workouts per week: “We ensure we’re swimming in the heat of the day and running and biking when it’s cooler, and we’ll pick bike routes that pass gas stations for ice to put in jerseys and sports bras,” says Jeff Bowman, owner and coach at Rev Tri Coaching in Tallahassee, Florida. During warm workouts, experiment with hydration to find the right balance of fluids and electrolytes for your needs, and practice drinking on the bike and on the run. When there’s a heat advisory, Bowman’s athletes move running and biking workouts indoors, where they can put in an intense effort with workouts such as the compound brick: “It’s pretty common for us to have to train inside—we’ll do run/bike/run/bike/run/bike (or vice versa) and increase the intensity each subsequent run/bike block,” he says. “But we make sure there’s air conditioning, fans directed at your face and body, and cool fluids.”

If the weather’s taking the life out of your workout, change plans: Join a spin class, pop in a workout DVD, or go for an aqua-jog. As long as you’re clocking at least three moderate to tough runs weekly (inside or outside), for at least half of your usual weekly volume, you’ll maintain base fitness and be able to ease back into your normal schedule as the days become more tolerable. When you’re enduring hot temps, trade heat-radiating roads and sidewalks for dirt or grass; run shaded loops where you can re-up on water and ice; and go by feel instead of pace.

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